4-Aryl-{60 -(1,4-benzodioxan-2-yl)-4-hydroxy-1-piperidineethanols

ABSTRACT

The compounds, 4-aryl- Alpha -(1,4-benzodioxan-2-yl)-4-hydroxy1-piperidineethanols, useful as anti-hypertensive agents.

United States Patent [1 1 Soudijn et al.

[ 5] Oct. 21, 1975 I 4-ARYL-a-( l,4-BENZODlOXAN-2-YL)-4- HYDROXY-l-PIPERIDINEETHANOLS [75] Inventors: Willem Soudijn, Turnhout; Ineke van Wijngaarden, Beerse, both of Belgium [73] Assignee: Janssen Pharmaceutical, N.V.,

Beerse, Belgium [22] Filed: Jan. 18, 1974 [21] Appl. No.: 434,477

[52] 'U.S. Cl 260/293.58; 424/267 [5 1] Int. Cl. C07D 211/52 [58] Field of Search 260/293.58

Primary ExaminerG. Thomas Todd Attorney, Agent, or Firm-Salvatore R. Conte [57] ABSTRACT The compounds, 4-aryl-a-( 1,4-benzodioxan-2-yl )-4- hydroxy-l-piperidineethanols, useful as antihypertensive agents.

6 Claims, N0 Drawings 4-ARYL-oz-( 1,4-BENZODIOXAN-2-YL )-4- HYDROXY- l -PIPERIDINEETHANOLS BACKGROUND OF THE INVENTION:

tained by reacting (III) with 2-epoxyethyl-l,4- benzodioxane (IV) in a suitable organic solvent, such as an aromatic hydrocarbon, for example, benzene, to]- uene, Xylene and the like; a halogenated hydrocarbon, such as chloroform and methylene chloride; or a lower alkanol such as, for example, methanol, ethanol, isopropanol and the like, and preferably in a mixture of an 5 aromatic hydrocarbon and a lower alkanol. The reac- The prior art discloses certain 2-(l,4-benzodioxan-2- tion may be promoted by the addition of alkali. yl)-2-hydroxyethylamine derivatives, not having said 4-aryl-4-hydroxypiperidine group. Such compounds 0 may be found in the following references: 0 J. Med. Chem., 13 2 169 1970 and 9 (1) JA 72.35435 Derw. Week 1972 T 36, Pharm. p. 31km 6. 0

DESCRIPTION OF THE INVENTION: (w) This invention relates to novel compounds, 4-aryl-a- 15 l,4-benzodioxan-2-yl) 4-hydroxy-l- The compounds of formula (I) may also be prepared piperidineethanols, which may be represented by the by the following reaction sequence. A compound of formula: formula (III) is reacted with an appropriate benzodioxan-2-yl-halomethyl ketone, preferably the bromo derivative of formula (V) in an appropriate organic solvent, 0 ()H such as, for example, a lower alkanol in the presence of a convenient acid acceptor, e.g., an amine, such as g j diisopropylamine. The resulting ketone of formula (VI) 0 is then reduced to the corresponding (I) by known methods such as, for example, with metal hydrides,

such as, sodium borohydride, sodium aluminumhyand the therapeutically active, non-toxic acid addition d id 'borane dib d th lik or ith a t l, salts thereof, wherein Ar is a member selected from the f bl an lk li t l i an appropriate l t group consisting of phenyl and substituted phenyl, the s ch as known in the art, e.g., liquid ammonia, lower latter being a phenyl group having one or more substitalkanol. The foregoing reactions are illustrated as foluents thereon, such as loweralkyl, loweralkyloxy, halo lows: I and trifluoromethyl. Preferably, the substituted phenyls are mono-, diand tri-substituted. As used herein, the 7 term loweralkyl represents O 11 straight and branch chained alkyls having from lto 5 C-CI-l Br carbon atoms and the term halo refers to halogens of g 3 acid acceptor (III) atomic weight less than 127, 1.e., chloro, bromo, fluoro 0 ethanol and iodo.

The subject compounds (I) are conveniently pre- (v) (KI) pared by reacting a compound of formula (II), wherein 40 0 OH X re sents a reactive ester of the corres ondin alco- 0 Li NaBH P P. g --CH N x hol, such as, tosylate, mesylate, and halide, preferably dioxane the bromide, with the amine of formula (III). This condensation reaction is conveniently conducted in an v inert organic solvent, such as, for example, an aromatic hydrocarbon, e.g., benzene, toluene, xylene and the The benzodioxane derivatives of formulas (II), (IV) like; a lower alkanol, e.g., methanol, ethanol, nand (V) are known. butanol, and the like; a ketone, e.g., 4-methyl-2- The 4-aryl-4-hydr0xypiperidines of formula (III) pentanone; an ether, e.g., dioxane, diethyl ether and which are for the most part also known may be obthe like; dimethylformamide (DMF); nitrobenzene; tained from methodologies available to one skilled in and the like. The addition of an appropriate base such the art. Such compounds and methods for preparing as, for example, an alkali metal carbonate or bicarbonsame are described in US. Pat. Nos. 2,973,363, ate, may be utilized to pick up the acid that is liberated 3,575,990 and 3,714,159. during the course of the reaction. Elevated tempera- The subject compounds (I) may be converted to their tures may be employed to enhance the rate of reaction. therapeutically active non-toxic acid addition salt form Cl-ICH -X HN Na Co a 3 Ar DMF (II) (III) Alternatively the compounds of formula (I) are 0bby treatment with an appropriate acid, such as, for example, an inorganic acid, such as a hydrohalic acid, e.g., hydrochloric, hydrobromic and the like, and sulfonic acid, nitric acid, phosphoric acid and the like; or

an organic acid, such as, for example, acetic, propionic, glycolic. lactic, pyruvic, malonic, succinic, maleic, fumaric, malic, tartaric, citric, benzoic, cinnamic. mandelic, methanesulfonic, ethanesulfonic, benzenesulfonic, p-toluenesulfonic, cyclohexanesulfamic, salicylic, p-aminosalicylic and the like acids. Conversely, the salt form can be converted by treatment with alkali into the free base form.

Typical compounds of formula (1) that may be prepared according to the processes described herein are:

a-( 1,4-benzodioxan-2-yl)-4-(p-ethoxyphenyl)-4- hydroxy- 1 -piperidineethanol;

a-( 1,4-benzodioxan-2-yl )-4-( 3,4-dimethylphenyl )-4- hydroxyl -piperidineethanol;

a-(1,4-benzodioxan-2-yl)-4-(2,4-dichlorophenyl)-4- hydroxyl -piperidineethanol;

a-( 1 ,4-benzodioxan-2-yl)-4-(2,4,6-trichlorophenyl )-4- hydroxyl -piperidineethanol;

a-( 1,4-benzodioxan-2-yl)-4-(2,4,6-trimethylphenyl )-4- hydroxy- 1 -piperidineethanol; and

a-( l,4-benzodioxan-2-yl)-4-(2-chloro-4- methylphenyl )-4-hydroxyl -piperidineethanol.

The compounds of formula (I), in base or acid addition salt form, have been found to possess marked blood pressure lowering activity, making them useful as anti-hypertensive agents. Blood pressure lowering activity was determined by the following procedure. Dogs were anesthetized with sodium pentobarbital (30 mg/kg i.p.). The arterial blood pressure was measured via an indwelling catheter, connected with an electronic pressure transducer. After the initial blood pressure was measured, the test compound was injected suboccipitally at dose levels of 2.5 and/or Lg/kg body weight. The results are illustrated in the following table. For each dose 2 to 6 dogs were used and the average of these experiments is presented.

It is understood that the compounds in the following table are not listed for the purpose of limiting the scope of the invention thereto but to exemplify the useful properties of all the compounds within the scope of formula (I).

H o i) CX H CH -c1-| Q j A r erythro blood pressure lowering effect at 2.5 .1g at 10 pg Ar per kg 5.0. per kg 5.0.

4-ClC H 42 mm. Hg 90 mm. Hg 4Br---C H 10 mm. Hg 22 mm. Hg 3CF;,C H,, 30 mm. Hg 50 mm. Hg 3CF 4Cl-C.,H mm. Hg 21 mm. Hg 4CH -C,;H 45 mm. Hg 40 mm. Hg

"suboccipital.

noted as erythro and threo forms, may be obtained separately, for example, by selective crystallization, by counter current distribution or by the unambiguous preparation of the desired form of (I) starting from the adequate form of (II). Said racemates may be further resolved into their optical enantiomers by methods known in the art, such as, by salt formation with optically active acids.

The following examples are intended to illustrate, but not to limit, the scope of the present invention. Unless otherwise stated, all parts are by weight.

' EXAMPLE 1 A mixture of 1.04 parts of erythro a-(bromomethyhl,4-benzodioxan-2-methanol, 0.765 parts of 4-(pchlorophenyl)-4-piperidinol, 0.64 parts of sodium carbonate and 6 parts of dimethylformamide is stirred overnight at 100C. The reaction mixture is cooled and diluted with 10 parts of water. The precipitated product is filtered off and crystallized from 2-propanol, yielding, after drying in vacuo at 50C., erythro a-( 1,4- benzodioxan-2-yl)-4-(p-chlorophenyl )-4-hydroxyl piperidineethanol; mp. 174.9C.

EXAMPLE II A mixture of 2.5 parts of erythro a-(bromomethyD- l,4-benzodioxan-2-methanol, 2.56 parts of 4-(pbromophenyl)-4-piperidinol, 1.6 parts of sodium carbonate and 15 parts of dimethylformamide is stirred overnight at 100C. The reaction mixture is cooled and filtered over hyflo. Upon the addition of water, the product is precipitated. It is extracted with chloroform and water. The chloroform layer is dried, filtered and evaporated. The residue is triturated in boiling ether. The product is filtered off and crystallized from 2- propanol, yielding erythro a-( l,4-benzodioxan-2-yl)-4- (p-bromophenyl )-4-hydroxyl-piperidineethanol; mp. 182.2C.

EXAMPLE [II EXAMPLE IV A mixture of 2.1 parts of erythro a-(bromomethyl)- l,4-benzodioxan-2-methanol, 1.52 parts of 4-p-tolyl-4- piperidinol, 1.27 parts of anhydrous sodium carbonate and 12 parts of dimethylformamide is stirred on a Water-bath at 90C for 16 hours. The reaction mixture is filtered over hyflo and the filtrate is diluted with water. The oily precipitate is extracted with chloroform. The extract is washed with water, dried, filtered and evaporated in vacuo. The residue is crystallized from 2- propanol. The product is filtered off and dried in vacuo at C., yielding erythro oz-( l,4-benzodioxan-2-yl)-4- hydroxy-4-p-tolyl- 1 -piperidineethanol; mp. l44.7C.

EXAMPLE V A mixture of 2.1 parts of erythro a-(bromomethyU- l,4-benzodioxan-2-methanol, 2.13 parts of 4-(4- chloro-a,a,a-trifluoro-m-tolyl)-4-piperidinol, 1.27 parts of sodium carbonate, and 12 parts of dimethylformamide is stirred overnight at l C. The reaction mixture is cooled, filtered over hyflo and water is added to the filtrate. The separated oily product is extracted with chloroform. The extract is dried, filtered and evaporated. The residue is purified by columnchromatography over silicagel, using a mixture of chloroform and 10% of methanol as eluent. The pure fractions are collected and the eluent is evaporated. The residue is converted into the hydrochloride salt in 2- propanol. The crude oily salt solidifies on triturating in ether. The solid salt is filtered off and crystallized from ethyl acetate, yielding erythro a-(l,4-benzodioxan-2- yl )-4-( 4-chloro-a ,a,a-trifluoro-m-tolyl )-4-hydroxyl piperidineethanol hydrochloride; mp. 2lO.2C.

We claim:

1. A compound selected from the group consisting of 4-aryl-o:-( l ,4-benzodioxan-2-yl)-4-hydroxyl piperidineethanols having the formula g j-jH-Cli O: 

1. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF 4-ARYLA-(1,4-BENZODIOXAN-2-YL)-4-HYDROXY-1-PIPERIDINEETHANOLS HAVING THE FORMULA
 2. Erythro Alpha -(1,4-benzodioxan-2-yl)-4-(p-chlorophenyl)-4-hydroxy-1-piperidineethanol.
 3. Erythro Alpha -(1,4-benzodioxan-2-yl)-4-(p-bromophenyl)-4-hydroxy-1-piperidineethanol.
 4. Erythro Alpha -(1,4-benzodioxan-2-yl)-4-hydroxy-4-( Alpha , Alpha , Alpha -trifluoro-m-tolyl)-1-piperidineethanol hydrochloride hydrate.
 5. Erythro Alpha -(1,4-benzodioxan-2-yl)-4-hydroxy-4-p-tolyl-1-piperidineethanol.
 6. Erythro Alpha -(1,4-benzodioxan-2-yl)-4-(4-chloro- Alpha , Alpha , Alpha -trifluoro-m-tolyl)-4-hydroxy-1-piperidineethanol hydrochloride. 